In some electronic device manufacturing systems, one or more process chambers may be arranged around a mainframe housing including a transfer chamber and one or more load lock chambers. The process chambers may perform one or more processes on a substrate (e.g., a wafer) inserted into the process chamber. Processing may include a chemical vapor deposition (CVD) process, such as plasma-enhanced chemical vapor deposition (PECVD) process that is used to deposit a thin film on the substrate. Other temperature-controlled processes may be carried out on the substrates, as well. During processing, wafers may rest on a support (e.g., a substrate platform) and the temperature thereof may be controlled (e.g., heated) at one or more times during the process. Conventionally, heating may be provided by resistive elements provided within the substrate pedestal.
It should be recognized, however, that even small variations in temperature across the substrate during such temperature-controlled processing may cause differential processing (e.g., possibly uneven deposition) or other processing deviations, which may be detrimental to achieving desired properties for the substrate.
Accordingly, apparatus and methods providing improved temperature monitoring and control in high-temperature substrate processing are desired.